Announcing the Community FlowSpec trial

Christopher Morrow morrowc.lists at
Wed Jan 5 22:26:21 CST 2011

On Wed, Jan 5, 2011 at 7:51 PM, Richard A Steenbergen <ras at> wrote:
> On Wed, Jan 05, 2011 at 05:46:36PM -0600, John Kristoff wrote:
>> Friends and colleagues,
>> At NANOG 48 I talked about a community flow-spec service we were
>> looking at trying to make work.  This is the idea of using IETF RFC
>> 5575 to pass around flow-based rules, in this case, primarily for
>> dropping unwanted packets.


> As a word of warning to anyone who wants to deploy this on their Juniper
> routers (what other router vendors support it? :P), there are some
> pretty serious performance considerations of which you should be aware.
> For example, we discovered that on MX routers (with classic I-chip DPCs,
> the performance should be somewhat better for Trio cards but we haven't
> fully tested the exact numbers yet), installing as few as a dozen
> flowspec routes can create firewall filters that use enough SRAM

'as few as a dozen' - of things like:
(forgive the hackery into cisco-ese)
deny ip any
permit ip any any

or with port/protocol/flags/sizes/etc ?
(can you provide some examples of your dozen-or-so - give folk a
starting point in their testing)


More information about the NANOG mailing list